Such a vehicle burner may be used, e.g., to heat an exhaust treatment means, which is arranged in an exhaust system of an internal combustion engine. The vehicle burner may be used to shorten the time that is needed to bring the exhaust treatment means to a minimum operating temperature or regeneration temperature, starting from which it can perform its exhaust treating function with sufficient effectiveness or the regeneration thereof. The vehicle burner is thus used to reduce pollutant emissions. It is also possible, in principle, to use such a vehicle burner in a vehicle-mounted heating means, which can be operated independently from an internal combustion engine of the vehicle, for example, in a standby heater or in a parking heater or in an auxiliary heater.
Such a vehicle burner may have a fuel pump for delivering a fuel to an injection nozzle, which can be actuated. Fuel can be injected into a combustion chamber by means of the injection nozzle, which can be actuated, a so-called injector. Furthermore, the vehicle burner comprises an air delivery and/or air regulating means, for example, a blower, pump or pressure source, for delivering air to the combustion chamber. A control provided for operating the vehicle burner is coupled with the fuel pump and with the air delivery and/or air regulating means as well as with the injection nozzle in a suitable manner. To set a predetermined heat output, the control actuates the injection nozzle to inject a quantity of fuel necessary for this and the air delivery and/or air regulating means for feeding a corresponding quantity of air. It is usual for the fuel pump to provide a constant fuel pressure during the operation of the vehicle burner, and the quantities of fuel injected into the combustion chamber can be set by means of the injection nozzle. For example, the injection nozzle may have different degrees of opening, which differ from each other by different flow resistances. In addition or as an alternative, the injection nozzle may be operated in a cyclic manner, in which case, in particular, the duration of opening and the cycle frequency can be set in order to make it possible to set the particular quantity of fuel in the manner of a pulse width modulation.
The quantity of air necessary for the particular quantity of fuel can be determined by a preset air ratio, the so-called lambda value or fuel-to-air ratio. The air ratio is usually selected to be such as to obtain the lowest possible pollutant emissions.